The present invention relates to a constant temperature type crystal oscillator (referred to hereunder as a “constant temperature oscillator”) for high stability, which uses a heating chip resistance, and in particular to a constant temperature oscillator having a heat transfer plate which improves the heat transfer efficiency between a crystal oscillator and the heating chip resistance.
In a constant temperature oscillator frequency stability is demanded. For example, constant temperature oscillators it are applied to base stations for mobile communications, and generally employ a constant temperature oven which makes the operating temperature of the crystal oscillator constant. Recently, with the miniaturization of electronic equipment including telecommunication devices incorporating such oscillators, the size of the constant temperature oscillator itself is required to be further miniaturized, particularly the height of the oscillator is required to be lower to make the oscillator thinner.